Kai Ryssdal: The center of the environmental universe this week is Rio de Janiero, Brazil. It's the United Nations Conference on Sustainable Development -- Rio+20, for short -- to recognize the first U.N. Earth Summit held in Rio 20 years ago. The big change this time is that businesses are going to be there too.

The working relationship between big companies and big environment has gotten better over the past two decades. They're not exactly best friends, but Marketplace's Eve Troeh reports from the Sustainability Desk, you could call 'em frenemies.

Eve Troeh: In northern California, Redwood country, the Garcia River used to run thick with silvery coho salmon. Today:

Jennifer Carah: They're down to less than 1 percent of their numbers from the 1950s and '60s, so they're in pretty dire straits.

Jennifer Carah is an ecologist with a nonprofit, The Nature Conservancy. She stomps through the river in waist-high waders, a hat over her blonde ponytail, to show me huge logs laid across the river.

Carah: The pieces that have the little orange flag and metal tags on them are pieces that we placed.

The tree trunks create shady pools, perfect for coho salmon to mate.

Carah: Fisheries biologists would come out and say this kind of thing a coho hotel, that's what they like to call 'em. Ooh, there's a fish by your foot. Do you ee it?

Troeh: Yeah!

It's tiny, about two inches long. The log hides this baby salmon from hungry birds. Carah works on her project with the very industry that destroyed the salmon's home. Lumberjacks help her harvest and position the thick tree trunks for this coho hotel.

Brian Stranko: There was a huge fight between folks who cared about conversation and timber folks. Literally people were chaining themselves to trees to not have trees cut.

Clashing at loggerheads didn't help either side. A few patches of forest got saved. But huge areas were completely cleared. Stranko says now both sides have the same goal: harvesting some trees, sustainably.

Stranko: So that we can have both a thriving economy up here and a healthy environment.

He says corporate funding is more important since the recession as public research money has dried up. But to find common ground, industry and NGOs have to talk it out. And they do. At a recent meeting in San Francisco, a group called the Future 500 brought together government, business and environmental groups to tackle recycling for product packaging.

Voices from Future 500 meeting: We know how to recycle a whole lot of materials, the question is who's going to pay for that? Here's in the U.S., taxpayers pay for the recycling of packaging. Recycling can be not just a cost to business, but also a benefit. There's a healthy tension in the room. The rules of engagement are that you have to come with a willingness to listen.

That last voice is Michael Washburn, director of sustainability for Nestle bottled waters. It's his first corporate job, after decades working for environmental groups. He was the guy running smear campaigns or filing lawsuits against business.

Michael Washburn: In the past you'd see companies and NGOs gathering in their respective spheres, and sort of lobbing messages at one another.

Now, he works to make Nestle Waters an environmental leader, starting with a goal to recycle half of all its plastic bottles. But Washburn says Nestle shouldn't bear that cost alone.

Washburn: Soup cans, tuna cans, paper boxes for cereal, other plastics for laundry detergent. You have to deal with this issue in a holistic way. It can't be just about beverage containers.

He wants NGOs to put pressure on other types of packaging. And for companies to step up -- stop making beverage brands take all the heat for their cans and bottles.

Jim Hanna is director of environmental impact for Starbucks. He says it's a friendly sparring match.

Jim Hanna: We all know each other, and we all know our tactics, and I think we all know our positions, where we're at. It's a pretty tight community.

That closeness can be risky. Take Starbucks' relationship with the social justice group Oxfam. A few years ago, Oxfam targeted Starbucks over coffee prices in Ethiopia.

Chris Jochnick: In a way, they deserve to be more exposed.

Chris Jochnick with Oxfam remembers a full page newspaper ad he helped write, against Starbucks.

Jochnick: They've built their reputation and the value of that brand around certain commitments. It's only right that they're held accountable for those commitments.

Jochnick says it's easier to campaign against companies than to work with them. Partnering consumes resources and time. Plus, it can alienate donors.

Jochnick: Oxfam also has to be considerate of our own brand.

But joining forces can lead to more progress, faster. Oxfam has a new program, enlisting companies to lobby for action on climate change. Starbucks has signed on. The company's environmental director, Jim Hanna, calls that evolution.

Hanna: Twenty years ago, it was a lot of protests, it was a real lack of engagement. I think what we've discovered, though, is that some of the strongest NGOs out there are the ones that choose to partner with corporations.

It's still an elaborate mating dance. But instead of stepping on each other's toes, this time in Rio more NGOs and companies are doing the samba together.

Eve Troeh is News Director at WWNO-FM in New Orleans, Louisiana, helping build the first public radio news department in the station’s 40-year history. She reported for the Marketplace Sustainability Desk from 2010 to 2013.